<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        table {
            width: 550px;
            border: 1px solid #ddd;    
            margin: 150px auto; 
        }
        td,th {
            border: 1px solid #ccc;
            text-align: center;
        }
    </style>
</head>
<body>
    <div id="app">
        <table>
            <caption>欢迎光临_vue开发的收银系统_水果店</caption>
            <tr><th>苹果10 ￥ / 斤，折扣&lt;8折&gt; </th></tr>
            <tr>
                <td>请输入你要购买的斤数 <input v-model="count" type="number"></td>
            </tr>
            <tr>
                <td><button @click="order">结账买单~</button></td>
            </tr>
            <tr>
                <td>结账单：总价：{{ total }} ￥元  折后价： {{ total * .8 }} ￥元 省了： {{ total * .2 }} ￥元</td>
            </tr>
        </table>
    </div>

    <script src="./vue.js"></script>
    <script>
        new Vue({
            el: '#app',
            data() {
                return {
                    count: 0,
                    total: 0
                }
            },
            methods: {
                order () {
                    // 根据输入的斤数算出总价
                    this.total = this.count * 10
                }
            }
        })
    </script>
</body>
</html>